2 Learn how to distract your child
If your child will not stop bouncing a ball against the window even after you have tried explaining to him why it is wrong, you can simply try to move him to another activity that he enjoys. Soon, he will forget about the ball. You do not need to worry that your child still has not learned that it is wrong to bounce a ball against the glass. He is incapable of understanding that at this age. He will understand in a year or two.